Conventional multi-drive network attached storage (NAS) devices use an internal an advanced technology extended (“ATX”) power supply and power backplane to interconnect and deliver power to its components. Typically, the power backplane distribute DC power, such as 5V and 12V power, from the power supply via power supply buses on the backplane. Unfortunately, these components can be susceptible to failure.
For example, ATX power supplies are subject to wear and tear due to power fluctuations, power surges, etc. Thus, ATX power supplies can be prone to failure. A failure in the ATX power supply may impact other sensitive components of the NAS device, such as the drives.
Power sequencing is one approach to reducing wear and tear on the power supply. Power sequencing is where the startup of individual drives of the NAS is staggered to reduce peak power draw and prevent overloading of the power supply. Typically, the individual drives of the NAS are connected to the power supply buses through switches, such as P-channel MOSFETs. Unfortunately, these switches in conventional backplanes are also known to be susceptible to failure and have poor performance, especially in isolating short circuit faults. Thus, even with the use of power sequencing, known NAS devices must use a higher rated ATX power supply than what would otherwise be necessary. This dramatically increases the cost of the NAS device and still does not address the underlying problems of conventional NAS devices and their backplanes.
As an alternative to power sequencing, some known NAS devices may employ fuses for protection. However, fuses still require an oversized power supply. Furthermore, fuses preclude the use of power sequencing.